Which boiler system is best?

housebuyer143

Section62 said:

housebuyer143 said:

The boiler unfortunately is beyond saving.. We bought the place a few months ago knowing it was old, but I have been told my s few people now that there are no parts for it as it's so old and to take it out and get a new one. 

Has it stopped working though?  Old boilers have relatively few moving parts that are likely to fail - one of them is the thermocouple which typically can be replaced with a generic one costing a few pounds.

People who can make a nice profit from installing a new (combi) boiler will be more than happy to convince you the existing boiler is both highly inefficient and impossible to repair.  What they won't mention is the combi will need more repairs and won't last very long.

The only absolutely sound reasons for getting rid of a working old boiler is if it is in a position where it will be in the way of (say) a kitchen replacement, or that not having a working boiler for a few days would be life endangering.  If you have a HWC and immersion heater then you aren't so critically reliant on the boiler not failing at an inconvenient time.

Thank you. It does have an intermittent F4 fault which seems to be okay after a reset 🤷‍♀️ I don't know how many times that will work for though. 

I might consider doing the tank in this case as it has that leak that can't wait a year and then address the boiler next year. 

I have been convinced into keeping my tank after the replies here, so thank you. 

molerat

housebuyer143 said:

Section62 said:

housebuyer143 said:

The boiler unfortunately is beyond saving.. We bought the place a few months ago knowing it was old, but I have been told my s few people now that there are no parts for it as it's so old and to take it out and get a new one. 

Has it stopped working though?  Old boilers have relatively few moving parts that are likely to fail - one of them is the thermocouple which typically can be replaced with a generic one costing a few pounds.

People who can make a nice profit from installing a new (combi) boiler will be more than happy to convince you the existing boiler is both highly inefficient and impossible to repair.  What they won't mention is the combi will need more repairs and won't last very long.

The only absolutely sound reasons for getting rid of a working old boiler is if it is in a position where it will be in the way of (say) a kitchen replacement, or that not having a working boiler for a few days would be life endangering.  If you have a HWC and immersion heater then you aren't so critically reliant on the boiler not failing at an inconvenient time.

Thank you. It does have an intermittent F4 fault which seems to be okay after a reset 🤷‍♀️ I don't know how many times that will work for though. 

I might consider doing the tank in this case as it has that leak that can't wait a year and then address the boiler next year. 

I have been convinced into keeping my tank after the replies here, so thank you. 

A few years back my son was told by both BG, who had virtually rebuilt the boiler replacing every part they could, and an indy boiler fitter that his boiler was beyond repair as it kept overheating and cutting out requiring a reset every few days.  As he couldn't afford it he asked me to have a look.  After doing a bit of proper fault diagnosis, something that seems to be beyond these boiler people, I found that the microswitch on the hot water zone valve was not sending the closed signal (well actually maintaining the open signal) to shut the boiler down.  Replacing the microswitch (from dad's box of might come in handy one day bits) got it functioning until I replaced the valve and head as the spindle was leaking allowing water into the motor head. So their diagnosis of the boiler being faulty was nothing of the sort and it is still working fine today.

goodwithsaving

I had this dilemma over combi or retain a cylinder not long ago having, just like you, moved into an existing installation. Also, once a boiler has started faltering I'm very much a 'rip it out and replace' type. Yes, it's expensive, but it's a gas appliance it's not the inconvenience of maybe having no hot water etc., it's the safety. If you're going to be there 10-20 years, I'd just install a completely new system.

I had always had combi's installed previously but in this house I went for an unvented cylinder set up (with a Hive for hot water and heating control). It's been brilliant. Consistently high pressure. My primary reason was to future proof. I'll get solar panels in a couple of years and want to be able to divert some of the energy into heating the hot water. You can't do that with a combi.
I also went for a larger tank than required. I don't use much water, but with a good tank the water is kept warm anyway, so I can take my time getting through it. I also don't know how many people will live here as life changes. 

Better to over spec than under spec, but don't have any qualms about pulling it out and starting from scratch....

housebuyer143

goodwithsaving said:

I had this dilemma over combi or retain a cylinder not long ago having, just like you, moved into an existing installation. Also, once a boiler has started faltering I'm very much a 'rip it out and replace' type. Yes, it's expensive, but it's a gas appliance it's not the inconvenience of maybe having no hot water etc., it's the safety. If you're going to be there 10-20 years, I'd just install a completely new system.

I had always had combi's installed previously but in this house I went for an unvented cylinder set up (with a Hive for hot water and heating control). It's been brilliant. Consistently high pressure. My primary reason was to future proof. I'll get solar panels in a couple of years and want to be able to divert some of the energy into heating the hot water. You can't do that with a combi.
I also went for a larger tank than required. I don't use much water, but with a good tank the water is kept warm anyway, so I can take my time getting through it. I also don't know how many people will live here as life changes. 

Better to over spec than under spec, but don't have any qualms about pulling it out and starting from scratch....

Thank you. You sound very much along my lines of thinking. If I am going to do it, I want it done right and done the best it can be, no cutting corners or cheaping out. 

I am thinking solar in a few years too and that would be a good thing to be able to do with the energy generated. 

Appreciate your reply. 

Section62

housebuyer143 said:

Thank you. You sound very much along my lines of thinking. If I am going to do it, I want it done right and done the best it can be, no cutting corners or cheaping out. 
 

It isn't cutting corners or 'cheaping out' to keep a perfectly serviceable boiler though.

As per molerat's post, there is a lot of pressure to dump whatever people have and replace it with a shiny new boiler, even if the boiler isn't the problem.

The "safety" argument is also misplaced.  A boiler isn't less safe because it throws out an error code, provided the fault is repaired by a competent gas safe engineer.  They won't leave a boiler operating in an unsafe condition.

housebuyer143

Section62 said:

housebuyer143 said:

Thank you. You sound very much along my lines of thinking. If I am going to do it, I want it done right and done the best it can be, no cutting corners or cheaping out. 
 

It isn't cutting corners or 'cheaping out' to keep a perfectly serviceable boiler though.

As per molerat's post, there is a lot of pressure to dump whatever people have and replace it with a shiny new boiler, even if the boiler isn't the problem.

The "safety" argument is also misplaced.  A boiler isn't less safe because it throws out an error code, provided the fault is repaired by a competent gas safe engineer.  They won't leave a boiler operating in an unsafe condition.

If course I agree, but I meant if it needs to be replaced then I like to do it right. 

Turns out my father in law who is an ex gas engineer is going to come up for a few days and take the tank apart and check it as he is convinced these tanks should last longer than this one has and thinks the leak could be a washer or something loose inside. Fingers crossed as that will save us so much money!

Bendy_House

It's very rare that the actual tanks themselves leak. Almost certainly it'll be a joint coming/going to it.

(In theory, you need to be G3-certified to work on such pressurised cylinders, certainly if being paid to do so. But, I guess as long as your fil is competent, there shouldn't be issues - but just letting you know )

Lost of good advice above, and the consensus would seem to be to remain 'stored' and pressurised/unvented. If/when you do fit PV, there are control devices that will automatically direct all surplus (ie - not being used by your household) generated electricity to an immersion heater, so that should make a significant difference.

There are other types of hot cylinder known as Thermal Stores, and these do a bit more - they are designed to store hot water at a higher temp, which is then used for both CH and the instant supply of DHW. So, if heating this tank using PVs was successful, the resulting hot water could be used to heat your house as well as give you nice showers. The system works by your boiler heating up this tank as required, so anything already managed by the PVs would have given it a head-start.

It would need someone with proper knowledge to work out if it would be a cost-saving system for you, tho'.

And I agree with others - try and nurse along what you have for as long as possible; that's the ultimate cost-saving!

BUFF

Section62 said:

housebuyer143 said:

The boiler unfortunately is beyond saving.. We bought the place a few months ago knowing it was old, but I have been told my s few people now that there are no parts for it as it's so old and to take it out and get a new one. 

The only absolutely sound reasons for getting rid of a working old boiler is if it is in a position where it will be in the way of (say) a kitchen replacement, or that not having a working boiler for a few days would be life endangering.  If you have a HWC and immersion heater then you aren't so critically reliant on the boiler not failing at an inconvenient time.

On the other hand, if he is taking a 10-20 year view, the old boiler is significantly less efficient than a new one & he has a largish gas consumption to go with his largish 4 bedroom house then the potential usage savings may well pay for the installation over the life of the boiler (mine has even though that has been at a far lower unit kWh rate than we currently have or will have from October 1st).
In any case, it is also probably worth looking at the controls in use & upgrading if they aren't up to snuff as they too may aid in making significant savings.

Bendy_House

I have to say that another reason I'd personally delay a boiler change  as long as possible is just to try and see what's going to happen with boilers/alternatives/energy supplies first.

ASHPs are almost certainly going to drop significantly in cost, for example. They might not be fully effective in a larger house, but backed up with PVs and a Thermal Store, they could be. At the moment, it's GAS prices that are mainly escalating in price, and electricity not so much. Will that remain the case? Will they even reach parity? Could ASHPs - even if they need a bit of extra help in deepest winter - become even less expensive to run than a gas boiler?

No idea

Section62

BUFF said:

Section62 said:

housebuyer143 said:

The boiler unfortunately is beyond saving.. We bought the place a few months ago knowing it was old, but I have been told my s few people now that there are no parts for it as it's so old and to take it out and get a new one. 

The only absolutely sound reasons for getting rid of a working old boiler is if it is in a position where it will be in the way of (say) a kitchen replacement, or that not having a working boiler for a few days would be life endangering.  If you have a HWC and immersion heater then you aren't so critically reliant on the boiler not failing at an inconvenient time.

On the other hand, if he is taking a 10-20 year view, the old boiler is significantly less efficient than a new one & he has a largish gas consumption to go with his largish 4 bedroom house then the potential usage savings may well pay for the installation over the life of the boiler...

20 years ago I would have agreed with you.  Now the situation is less clear and with uncertainty over the price (and future) of gas, it isn't possible to say that investing in a more efficient gas boiler to save money is an "absolutely sound" reason.

Before the Russian invasion of Ukraine the government had already made it clear they want us to stop using gas for domestic heating.  The Russian invasion has burst the bubble of very cheap gas.  Even after a cessation of war, there is no certainty we will go back to the days of gas costing a few pennies per kWh.

Whilst an increase in the cost of gas would in principle give greater potential to recoup the cost of (say £3000) investing in a new (more efficient) boiler, we can't exclude the possibility that the cost of electricity to run a heat pump (plus capital+maintenances costs) won't become cheaper within (say) a 10-year time frame.

If you knew that a new gas boiler will last 10 years (we don't) and that gas CH will be cheaper to run than alternatives (we don't) then it would be an absolutely sound reason to replace the existing boiler asap.  But as things stand it is a gamble - with £3k+ of capital money.  As you say yourself, it "may well pay" rather than "will pay".

My own POV is that there may be future incentives offered to homeowners to replace their gas boiler with a heat pump.  A new version of the gas boiler scrappage scheme.  If so, then logically the scheme will target the least efficient gas boilers (those producing more excess CO2), rather than subsidising the scrapping of super-duper efficient gas boilers which are only a few years old. (again, no guarantees though).  On balance I would do what I could to preserve my potential eligiblity for a scrappage/HP scheme as long as I could. 

Therefore the decision to replace an old gas boiler has got to be taken on the basis of either -

1) Replacing the boiler because it has stopped working (or failure is known to be imminent) and it has become a question of comfort/necessity

2) There's an economic advantage to replacing the boiler now - which, with the cost/future of gas so uncertain, means making a decision which amounts to a gamble.

The days of 'rip it out and start again' being the automatic answer have passed.  Folk (generally) need to adjust their thinking to the new dynamics of domestic heating.  (And some gas boiler installers will be the last to admit that).